Bugfix woocommerce plugin

I have a custom shipping gateway per product plugin for woocommerce. Here you can select per product what shipping gateway must be used. If multiple products with different shipping gateways it must show the hateway that is set in settings when multiple products are in the card. It must show: None or cheapest or expensive method only. This is not working anymore. The programmer who build this plugin is not available anymore. So i need someone that can code not design. budget is round 30-40 us dollars for this small bugfix